BAGHDAD, Iraq (CNN) -- The U.S. monthly troop death toll in Iraq is down by almost 50 percent so far in October, a sign of growing security gains across the nation.

There have been 13 U.S. troop deaths in Iraq, compared with 25 in September. It is the second-lowest monthly troop death toll in the war, with July the lowest at 11.

At the same time, the monthly Iraqi civilian death toll also dropped in October, an Iraqi Interior Ministry official said.

Listing figures from the Interior, Health and Defense ministries, the official said 278 civilians were killed and 464 wounded this month, compared with 359 killed and 705 wounded in September.

The official said it is likely the lowest monthly civilian death toll since the February 2006 bombing of Al-Askariya Mosque in Samarra, an event that caused widespread sectarian warfare.

Twenty-two police were killed and 64 were wounded in October, compared with 56 killed and 145 wounded in September. Eighteen soldiers were killed and 40 were wounded, compared with 26 killed and 41 wounded in September.

Of the 13 Americans killed in October, six died in noncombat incidents and seven in hostilities. Of the 11 in July, five died in noncombat incidents and six in hostilities.